1 files changed, 28 insertions, 9 deletions

diff --git a/hw/xen/xen-bus-helper.c b/hw/xen/xen-bus-helper.c
index b2b2cc9..288fad4 100644
--- a/hw/xen/xen-bus-helper.c
+++ b/hw/xen/xen-bus-helper.c
@@ -105,25 +105,22 @@ int xs_node_vscanf(struct qemu_xs_handle *h,  xs_transaction_t tid,
                    const char *node, const char *key, Error **errp,
                    const char *fmt, va_list ap)
 {
-    char *path, *value;
+    char *value;
     int rc;
 
-    path = (strlen(node) != 0) ? g_strdup_printf("%s/%s", node, key) :
-        g_strdup(key);
-    value = qemu_xen_xs_read(h, tid, path, NULL);
-
-    trace_xs_node_vscanf(path, value);
+    if (node && strlen(node) != 0) {
+        value = xs_node_read(h, tid, NULL, errp, "%s/%s", node, key);
+    } else {
+        value = xs_node_read(h, tid, NULL, errp, "%s", key);
+    }
 
     if (value) {
         rc = vsscanf(value, fmt, ap);
     } else {
-        error_setg_errno(errp, errno, "failed to read from '%s'",
-                         path);
         rc = EOF;
     }
 
     free(value);
-    g_free(path);
 
     return rc;
 }
@@ -142,6 +139,28 @@ int xs_node_scanf(struct qemu_xs_handle *h,  xs_transaction_t tid,
     return rc;
 }
 
+char *xs_node_read(struct qemu_xs_handle *h, xs_transaction_t tid,
+                   unsigned int *len, Error **errp,
+                   const char *path_fmt, ...)
+{
+    char *path, *value;
+    va_list ap;
+
+    va_start(ap, path_fmt);
+    path = g_strdup_vprintf(path_fmt, ap);
+    va_end(ap);
+
+    value = qemu_xen_xs_read(h, tid, path, len);
+    trace_xs_node_read(path, value);
+    if (!value) {
+        error_setg_errno(errp, errno, "failed to read from '%s'", path);
+    }
+
+    g_free(path);
+
+    return value;
+}
+
 struct qemu_xs_watch *xs_node_watch(struct qemu_xs_handle *h, const char *node,
                                     const char *key, xs_watch_fn fn,
                                     void *opaque, Error **errp)